Applications
MADflow features a range of widely adopted rheological constitutive relationships and has undergone rigorous validation and calibration through extensive laboratory experiments and/or field case history matching, encompassing diverse mass properties. Furthermore, default incorporation of the Mohr–Coulomb failure criterion enhances frictional-based models. Users can manually adjust lateral pressure yield ratios for both active and passive states as needed.
The Manning or Voellmy turbulent effect can be added to either the friction model or visco-plastic models (Bingham or Herschel-Bulkley).
Entrainment and erosion models include linear and power-law formulations, Hanson's hydraulic erosion mechanism and simplified Soulsby-van Rijn sediment transport formula.
Rheology Models
| Model | Description |
|---|---|
| Bingham | flow shear resistance is a function of the constant Bingham yield stress and Bingham dynamic viscosity. |
| Coulomb Viscous | flow shear resistance is a combination of yield stress, frictional resistance and viscous resistance, which couples particle-particle interaction in a viscous fluid between the intervening lubrication layer of fluid and the deformation of solid particles. |
| Frictional | flow shear resistance is a function of flow depth, coefficient of apparent / dynamic friction (which is a function of shear stress and normal stress). |
| Herschel-Bulkley | flow shear resistance is a function of yield stress, a consistency index, and a flow behavior index associated with shear-thinning or shear-thickening behavior. |
| Plastic | flow shear resistance is controlled by a constant strength, such as residual undrained shear strength of the mobilized material. |
| Quadratic | flow shear resistance consists of Bingham viscous stress and dispersive / turbulent components in a higher order term which is combined into an equivalent Manning’s coefficient. |
| Sassa | flow shear resistance is a function of flow depth, a constant cohesion and an apparent frictional angle. |
| Voellmy | flow shear resistance consists of a frictional term and a turbulent term which relates to flow velocity and a turbulent coefficient, and empirically accounts for possible sources of velocity-dependent resistance during runout. |
Selected Technical Papers
- Chen, H. (2022). Hydraulic Erosion in Tailings Dam Breach Analysis. Proc. The 2022 Tailings and Mine Waste Conference. Denver, United States, Nov. 6-10, 2022.
- Ghahramani, N., Chen, H., Clohan, D., Liu, S., Llano, M., Rana, N., McDougall, S., Evans S. and Take, A. (2022). A Benchmarking Study of Four Numerical Runout Models for the Simulation of Tailings Flows. Science of the Total Environment, 827, 154245.
- Chen, H. and Cunning, J. (2021). Application of Critical State Soil Mechanics in Tailings Dam Breach Analysis. Proc. Canadian Dam Association 2021 Annual Conference. Oct. 25-28, 2021.
- Chen, H., Chin, B. and Friedel, R. (2019). Dam Breach Tailings Runout Modelling for Inactive/Closed Tailings Storage Facility. Proc. Canadian Dam Association 2019 Annual Conference. Calgary, Canada, Oct. 6-9, 2019.
- Chen, H. and Becker, D. (2014). Dam Breach Tailings Runout Analysis. Proc. Canadian Dam Association 2014 Annual Conference. Banff, Canada. Oct. 4-9, 2014.
- Chen, H. and Lee, C.F. (2007). Landslide Mobility Analysis using MADflow. Proc. Int’l Forum on Landslide Disaster Management. Geotechnical Division, Hong Kong Institution of Engineers. 2: 857-874.
- Chen, H., Crosta, G.B. and Lee, C.F. (2006). Erosion Effects on the Runout of Fast Landslides, Debris flows and Avalanches: A Numerical Investigation. Géotechnique 56(5): 305-322.
- Crosta, G.B., Chen, H. and Frattini, P. (2006). Forecast Hazard Scenarios and Evaluate Countermeasure Efficiency for Large Debris Avalanches. J. Engineering Geology 83: 236-253.
- Crosta, G.B., Frattini, P., Fugazza, F., Caluzzi, L. and Chen, H. (2005). Cost-benefit Analysis for Debris Avalanche Risk Management. Int’l conf. on landslide risk management, 18th Annual Vancouver Geotechnical Society Symposium Canada. May 31 - June 4.
- Crosta, G.B., Chen, H. and Lee, C.F. (2004). Replay of the 1987 Val Pola Landslide, Italian Alps. Geomorphology 60: 127-146.
- Chen, H. and Lee, C.F. (2003). A Dynamic Model for Rainfall-induced Landslides on Natural Slopes. Geomorphology, 51: 269-288.
- Chen, H. and Lee, C.F. (2002). Runout Analysis of Slurry Flows with Bingham Model. ASCE J. Geotechnical and Geoenvironmental Engineering, 128(12): 1032-1042.
- Chen, H. and Lee, C.F. (2000). Numerical Simulation of Debris Flows. Canadian Geotechnical J. 37: 146-160.
- Chen, H. and Lee, C.F. (1999). Three-dimensional Numerical Modelling of Muddy Debris Flows. Proc. Int’l Symposium on Slope Stability Engineering, Japan. 2: 1397-1402.